International Psoriasis Council

Advancing Knowledge. Improving Care.

Advancing Knowledge. Improving Care.

Generalized Pustular Psoriasis

OVERVIEW OF GENERALIZED PUSTULAR PSORIASIS

Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening form of psoriasis that can present at any age, but the median age is around 50. GPP is characterized by widespread areas of inflamed skin with pustules, and its severity can fluctuate, with periods of flare-ups followed by remission. Flares may be triggered by multiple factors, such as rapid withdrawal of systemic corticosteroids, infections, pregnancy, and even stress.

The etiology of GPP is not fully understood. However, it is believed to involve a combination of genetic (e.g., IL36RN), environmental, and immune system factors (e.g., higher levels of IL-1 and IL-36, lower levels of IL-17A and INF-gamma than in psoriasis). The only approved treatment option for GPP is spesolimab (intravenous and subcutaneous). Intravenous spesolimab is approved for flares in some countries (e.g., US, Japan, China, Taiwan, and Canada). While subcutaneous spesolimab for flare prevention in the US and China. Other treatment options include non-biologic system therapies. Meanwhile, subcutaneous spesolimab has been approved for flare prevention in the US and China. Finally, the role of the IL-36 pathway as a key inflammatory factor in GPP is currently driving the development of new treatments.

Fast Facts

  • GPP is a rare and potentially life-threatening form of psoriasis.
  • GPP-specific assessment tools, Generalized Pustular Psoriasis Area and Severity Index (GPPASI) and the Generalized Pustular Psoriasis Physician Global Assessment (GPPGA), have been developed and validated, showing they are valid, reliable, and responsive measures.
  • There is only one approved GPP-specific treatment (intravenous and subcutaneous spesolimab) in several countries, either for flares or flare prevention, respectively.
  • New GPP treatment options are being developed focused on the IL-36 pathway.

IPC Resources

PUBLICATIONS AND RESEARCH

The Experts

Hervé Bachelez Headshot

Hervé

Bachelez

,

MD, PhD

Hôpital Saint-Louis, Imagine Institute for Human Genetic Diseases, Paris Cité University
Paris
,
France

Siew Eng

Choon

,

MBBS, FRCP

Hospital Sultanah Aminah Johor Bahru, School of Medicine and Health Services, Monash University Malaysia
Johor
,
Malaysia

Additional Resources

VALIDATED SCORING TOOLS FOR GPP

GPP-specific assessment tools (i.e., Generalized Pustular Psoriasis Area and Severity Index (GPPASI) and Generalized Pustular Psoriasis Physician Global Assessment (GPPGA)) have been developed and validated.2, 3 The validation of GPPGA showed that the score effectively evaluates GPP severity, making it a valuable resource for clinicians and researchers in monitoring and managing this challenging condition.2 In addition, both GPPGA and GPPASI had psychometric validation, which showed they were valid, reliable, and responsive measures in assessing GPP disease severity.3

GPPGA score is based on the mean score of the three parameters assessed
(Image 1: GPPGA severity criteria | Image 2: GPPGA score)

  • Clear: 0 if the mean score is 0
  • Almost Clear: 1 if the mean score is > 1 and < 1.5
  • Mild: 2 if the mean score is ≥ 1.5 and < 2.5
  • Moderate: 3 if the mean score is ≥ 2.5 and < 3.5
  • Severe: 4 if the mean score is ≥ 3.5

GPPASI (is based on a numeric score for a patient’s overall disease state, with a range of 0–72
(Image 3: GPPASI score)

  • The GPPASI score is a measure of the average redness, pustulation, and scaliness of GPP lesions (each graded on a scale of 0–4), weighted by the area of involvement in four regions (head 10%, upper limbs 20%, trunk 30%, and lower limbs 40%)
OTHER SCORING TOOLS FOR GPP

JDA-GPPSI4

  • The Japanese Dermatological Association Severity Index of GPP (JDA-GPPSI) can assess GPP severity based on skin symptoms and systemic involvement.
  • The JDA-GPPSI classifies disease severity as mild (0–6), moderate (7–10), or severe (11–17)
  • Validation is still needed.
PUBLICATIONS AND RESEARCH

Generalized Pustular Psoriasis: A Global Delphi Consensus on Clinical Course, Diagnosis, Treatment Goals and Disease Management.
Puig L, Choon SE, Gottlieb AB, Marrakchi S, Prinz JC, Romiti R, et al. J Eur Acad Dermatol Venereol. 2023;37(4):737-52.

Generalized Pustular Psoriasis: A Review on Clinical Characteristics, Diagnosis, and Treatment.
Rivera-Diaz R, Dauden E, Carrascosa JM, Cueva P, Puig L. Dermatol Ther (Heidelb). 2023;13(3):673-88.

Clinical Disease Measures in Generalized Pustular Psoriasis.
Burden AD, Choon SE, Gottlieb AB, et al.. Am J Clin Dermatol. 2022;23(Suppl 1):39-50.

Adalimumab Treatment in Japanese Patients with Generalized Pustular Psoriasis: Results of an Open-label Phase 3 Study.
Morita A, Yamazaki F, Matsuyama T, Takahashi K, Arai S, Asahina A, et al. J Dermatol. 2018;45(12):1371-80.

European Consensus Statement on Phenotypes of Pustular Psoriasis.
Navarini AA, Burden AD, Capon F, Mrowietz U, Puig L, Koks S, et al. J Eur Acad Dermatol Venereol. 2017;31(11):1792-9.

WEBSITES

IRASPEN Registry
The International Rare And Severe Psoriasis Expert Network (IRASPEN) Registry aims to harmonize the phenotypic descriptions and diagnostic criteria for pustular psoriasis.

Global Psoriasis Atlas: Pustular Psoriasis Research Progress
A resource to review information and research on GPP

National Psoriasis Foundation: Pustular Psoriasis
NPF provides general information on GPP

DermNet: Generalised Pustular Psoriasis
A general resource for information on GPP, including causes, clinical features, diagnosis, and treatment

References

  1. Clinical Disease Measures in Generalized Pustular Psoriasis. Burden AD, Choon SE, Gottlieb AB, Navarini AA, Warren RB. Am J Clin Dermatol. 2022;23(Suppl 1):39-50.
  2. The Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) score: online assessment and validation study of a specific measure of GPP disease activity. Burden AD, Bachelez H, Choon SE, Marrakchi S, Tsai TF, Turki H, et al. Br J Dermatol. 2023;189(1):138-40.
  3. Psychometric validation of the generalized pustular psoriasis physician global assessment (GPPGA) and generalized pustular psoriasis area and severity index (GPPASI). Burden AD, Bissonnette R, Lebwohl MG, Gloede T, Anatchkova M, Budhiarso I, et al. J Eur Acad Dermatol Venereol. 2023;37(7):1327-35.
  4. Adalimumab treatment in Japanese patients with generalized pustular psoriasis: Results of an open-label phase 3 study. Morita A, Yamazaki F, Matsuyama T, Takahashi K, Arai S, Asahina A, et al. J Dermatol. 2018;45(12):1371-80.

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